Apply to go up and down (5)
I believe the answer is:
refer
I believe this is a triple definition!
'apply to' is the first definition.
(thesaurus)
'go' is the second definition.
(thesaurus)
'up and down' is the third definition.
(Other definitions for refer that I've seen before include "Send or direct to a specialist" , "Turn to (for information, authorisation etc)" , "guide" , "Mention/allude (to)" , "Hand over for consideration (to)" .)